Apparatus for mixing molding sand



Nov. 26,v 1940. A. c. CHRXSTENSEN 2,223,018

APPARATUS FOR MIXING MOLDING SAND Filed May 3, 1937 Patented Nov. 26, 194()l PATENT OFFICE l 2,223,018 nPEAaaTUszFomvnxmG MoLDLNG SAND Alfred. C'. Christensen,v Chicago, Ill., assignmtov Herbert S. Simpson, Chicago, Ill.

Application May s, 1937,A seriaiNo. 140,324

My invention relates to improvements in mixing apparatus and similardevices. My inventionrelates more particularly to anew and improved mechanism for mixing pulveran-t or gran- I ular materials and for mixing orblending such materials withliquids or semi-solid substances to form a thoroughly comingl'ed mass.

The pri-'ncipal object of the present invention l is to. provide an improved means and apparatus for thoroughly comingling materials such as cl'a-y, sand? and` water for molding purposes.

A further object of the invention is to provide an improved mechanism for intermingli'ng the elements above described so that they may be 18 thoroughly and completely intermixed in the minimumamount oftime.

A further object of the invention is to provide an apparatus of the type described that is capable of carrying out my new and improved 20 method. l I

A further object of the present invention is to provideimproved mechanism of' the type described that iscomparatively# simple in construction, easy in operation, and Jthat will not easily become broken or out of order.

A further object of the invention is to provide an improved apparatus of the type described which may be horizontally or vertically positioned and operate equally as effectively in either po- 30 sition.

Other objects and advantages will be more apparent from the following description wherein reference is had to the accompanying two sheets of drawings upon which Fig. 1 is a plan view of my improved mixing mechanism with parts of the top broken away in section to more clearly show parts therebelow;

Fig. 2 is a vertical cross-sectional view taken generally on the lines 2 2 of Fig. 1;

In the mixing of a molding compound, it is well known in foundry practice that one advantageous type of material is a mixture of sand, clay and water. The mixture is preferably obtained by 45 any action which passes the relatively heavier sand through the clay and water in such ay manner that each individual grain of sand receives a coating or covering of clay. Sand that has been treated in this manner has been found 50 to be the most desirable for use for certain types of molding.

Accordingly, in the mixer which I have shown,

Y I have provided, as shown in Figs. 1 and 2, a

1,horizontally disposed drum I Il formed with the 55 parallel top and bottom walls I2 and I4 and. the

(or. g-7;)

vertical cylindrical wall I6. I provide a pair of bearings, I8 and 20, inthe upper'and lower walls I2 and I 4 of the drum to support a vertical axially disposed shaft 22.

Means for driving the shaft 22 may comprise an angularly disposed end' portion 3.8 that isalso extendedi'upwardly with the outer edge parallel to the wall .of the drum andthe inner edge 33a angularly disposed towards the blade 34.

AA hopper 38 maybe mounted upon the top wall I4 of `the drum and isprovided with a door 40, which .may be opened or closed as desired, to permit the introduction of. thesand, water and i clay. An. outlet or a discharge chute 42 may be provided in the vertical wall IG of the drum. I

provide an air operated discharge door 44 connected to a cylinder 46 to which a source of airr may be connected. In this manner, by the use of the air operated cylinder, the door may be opened or closed as desired.

The drum I0 may be mounted upon a plurality of feet 48 positioned upon suitable blocks 56 of a desired heighth, so that the entire mechanism may be easily and conveniently positioned for operation where desired. In the operation of my improved mixer, when a quantity of sand, clay and water has been placed in the drum IIl with the inlet door 4I] and the outlet door 44 closed, the motor 24 may be started to commence the mixing operation. As the spideris driven by the motor, the mass in the drum will be raised and at the same time be .forced forwardly and outwardly against the vertical walls ofthe drum. As this agitation becomes more rapid, so that the end portion 36 of the blade rotates at the rate of about 2000 feet per minute, the particles of sand particularly will be thrown with greater force through the lighter materials, thus receiving a coating of clay in the process. As the heavier materials are thrown against the walls I6 of the drum, the forwardly inclined extensions of the blades 34, have a tendency to throw them back toward the center I ll() of the drum, and thus there is constant repetition of the coating process.

By the actions thus described, it can be seen K have found that by the combination of the actions provided, a very effective mixing of the sand and clay is obtained and an extremely; desirable product is produced thereby. A ."'1 While I have illustrated and described apreferred form of the structure employed, it. will be obvious to those skilled in the art that changes and modifications can readily be made in the detailed features shown. What I desire to secure and protect by Letters Patent of the United States is:v y

1. Apparatus of the class described comprising a stationary closed drum, a vertical axial shaft therein, a spider mounted thereon located in close proximity to the base of. said drum, means for rotating said spider, said spider having a ,plurality of blades having upwardly disposed portions at their extensions, the Aextensions `of said, blades being adjacent the walls of said `drum and said extensions being angularlyV disposed forwardly from said spider.

2. Apparatus of the class described comprising a stationary closed drum, a vertical axial shaft therein, a spider mounted thereon located ,in close proximity to the base of said drum, means for rotating said spider, said spider havingv a plurality of blades positioned at right angles to each other and having upwardly disposedy portions attheir outer extensions, the*v extensions'of said blades being adjacent the walls of said drum and said extensions being angularly disposed forwardly from said spider whereby the leading 4edge of each blade is in advance of the blade. 4

3. Apparatus of the class described comprising a horizontal closed drum having vertical walls, a

vertical axially disposed shaft mounted therein, means for driving said shaft and a spider mounted upon said shaft, said spider being disposed in a horizontal position and situated in close proximity to the base of said drum and having a plurality of radially extending arms, said arms formed with forwardly inclined ends adapted to lie adjacent the vertical walls of said drum, said spider being adapted to hurl' ingredients in said drum against the walls thereof at relatively high speed.

4. Apparatus forblending or coating molding sand comprisingpa circular closed drum, a vertical shaftptherein, a spider mounted thereon,

means for'rotating said spider at relatively high 'speed,.said'spider having a plurality of blades positioned at right angles to each other, the extensions of said blades being adjacent the walls of said drum and said extensions being angularly disposed forwardly from said spider whereby the leading edge of'each bladeis in advance of the blade.

5. Apparatus of the class described comprising a circular closed drum, an axial'shaft therein, a

spider mounted thereon and located in close proximity to the base of said drum, means for rotating said spider at relatively high speed, said spider having a plurality of blades having angularly disposed portions at their extensions, the extensions of said blades beingadjacent the walls of said drum and Asaid extensions being and theheavier particles'of-materials are moved through the lighter particles and become'coated with.` the latter. y l j ALFRED C. CHRISTENSEN. 

